NHTSA Office of Defects Investigation

Engineering Analysis EA17-002: Exhaust Odor in Passenger Cab

  • Closed

NHTSA's Office of Defects Investigation opened Engineering Analysis EA17-002 on July 27, 2017 and closed it on January 17, 2023. NHTSA's investigations file lists the Ford Explorer and Explorer Police Intercept for it.

Updated daily from NHTSA's investigations file

Key facts

NHTSA number
EA17-002 (also written EA17002)
Investigation type
Engineering Analysis A more detailed stage of a defect investigation, opened when NHTSA's Office of Defects Investigation decides an issue merits further review, often after a Preliminary Evaluation or a Recall Query; it can include vehicle testing, surveys and further information requests.
Status
Closed January 17, 2023
Opened
Closed
Vehicle or equipment manufacturer
Ford Motor Company
Components
Engine and Engine Cooling — Exhaust System — Manifold/Header/Muffler/Tail Pipe; Structure — Body
Vehicles and equipment
Ford Explorer and Explorer Police Intercept

A recall appears here only when NHTSA's investigations file links one to the investigation; NHTSA's summary or record can name others.

NHTSA's summary

As NHTSA's Office of Defects Investigation wrote it for Engineering Analysis EA17-002.

During the EA17-002 investigation, the agency reviewed and analyzed reports of exhaust odors in the passenger cabins of Model Year 2011 to 2017 Ford Explorers. This investigation required an approach that incorporated knowledge and expertise from the automotive, medical, environmental health, and occupational safety fields. The agency conducted an in-depth investigation that encompassed the review of over 6,500 consumer complaints, conducting field inspections, and testing the relevant vehicles, both independently and in coordination with Ford and other entities. During the investigation, the evolution of Ford service bulletins intended to reduce the level of exhaust odors and carbon monoxide (CO) entering the occupant compartment was examined and independent tests to evaluate the effectiveness of the final Field Service Actions (FSA) for both consumer and police vehicles were conducted. As part of the investigation, the agency also examined the effects of cracked exhaust mani-cats on the measured CO levels in the vehicles and tested the FSA repairs to ensure they did not adversely impact occupant compartment CO levels due to cracked mani-cats.

The investigation identified upfitting issues for Police Interceptor vehicles. Upfitting (sirens, lights, cages, auxiliary power, etc.) is typically performed by governmental fleet operations, independent repair facilities, or local Ford dealers after the sale of the new vehicle. Sealing issues caused by upfitting were responsible for the highest measured carbon monoxide levels in tested vehicles. The police FSA instructs how to inspect the quality of the vehicle upfits and how to properly seal any leaks caused by these upfits, at no cost to the police agency. Similarly, the highest CO levels measured in consumer vehicles were usually traced to sealing issues caused by rear crash damage where the repairs did not ensure sealing integrity. The most recent Ford FSA procedure for both the police (17B25) and consumer vehicles (17N03) includes an HVAC reprogramming operation. Tests by Ford and NHTSA have demonstrated a substantial reduction of CO levels due solely to the HVAC reprogramming. Other FSA repairs also demonstrated measurable contributions to CO level reductions during controlled tests.

Throughout the investigation, vehicles accurately measured with higher levels of carbon monoxide were almost always affected by upfitter alterations, damage, or other causes compromising rear passenger cabin seals.

NHTSA received thousands of reports alleging odors which triggered a variety of physiological responses, predominately nausea, headaches, and lightheadedness. NHTSA focused the investigation on accurately measuring vehicle CO levels, and accurately measuring carboxyhemoglobin (COHB) levels from properly administered blood tests. Using rigorous test methods to produce exhaust gas intrusion in vehicles with a properly performed FSA, occupant compartment CO levels remained below current environmental limits for CO in any environment (EPA ambient air quality standards). Furthermore, even without FSA repairs, no vehicles unaffected by upfitter issues or prior crash damage were identified with CO levels that exceed accepted occupational CO exposure levels. This investigation finds that the 2011-2017 Ford Explorer vehicles when accurately measured produce occupant compartment CO levels which fall below current accepted health standards, and could not identify COHB levels for vehicle drivers or other occupants, which exceeded thresholds for acute physiological effects. Therefore, the agency has not identified a defect that represents an unreasonable risk to motor vehicle safety.

This inve

Vehicles and equipment listed for this investigation

NHTSA's investigations file lists these vehicles and equipment for Engineering Analysis EA17-002. A listed model year means only that an investigation names it; it says nothing about any particular vehicle. Model years with a try.vin recall page link to that page's NHTSA investigations section.

Ford

All Ford recalls

What an NHTSA investigation is

NHTSA's Office of Defects Investigation (ODI) looks into possible safety defects in vehicles and equipment, often after owner complaints. An investigation usually starts as a Preliminary Evaluation, or as a Recall Query when it concerns whether an existing recall covers the right vehicles or fixes the problem, and ODI can upgrade it to a more detailed Engineering Analysis. A Defect Petition asks NHTSA to open an investigation, and Audit and Equipment Queries are administrative investigations into whether companies complied with federal vehicle safety requirements, such as reporting, recall and certification rules.

An open investigation is not a finding that a safety defect exists, and NHTSA can close one without a recall.

To see whether a specific vehicle has an open recall, enter its VIN at nhtsa.gov/recalls.

Ford VIN check: decode a VIN to see its year, make and model.

Sources

NHTSA's investigation record for EA17-002

Investigation details come from NHTSA's investigations file, which try.vin imports once a day. The investigation types are described from the U.S. Department of Transportation Inspector General's May 2023 report on NHTSA's Office of Defects Investigation, NHTSA's petition rules (49 CFR Parts 552 and 557) and NHTSA's Office of Defects Investigation procedures. How try.vin reads NHTSA investigations.